Inflammasome activation in human trophoblast cells and placenta. (A-E) Platelets enhance ATP-dependent EV-mediated (human umbilical vein endothelial cell–derived EVs) inflammasome activation in human trophoblast cells. (BeWo cells; A, representative immunoblots). EV-mediated inflammasome activation in BeWo cells is enhanced in the presence of PRP (EV+PRP) compared with EVs only (EV) or EVs with PPP (EV+PPP). EV-induced platelet-mediated inflammasome activation (EV+PRP) in BeWo cells is reduced using apyrase (EV+PRP+Apyrase), oATP (EV+PRP+oATP), or when using platelets from donors receiving aspirin (EV+ASA-PRP). (B-D) Inflammasome activation in human placentae obtained from women without pregnancy complications (controls; C) or with PE. Dot plot (B) showing increased cleavage of Casp-1 and IL-1β in PE vs controls, whereas NLRP3 expression does not change. Representative images (C) for proximity ligation assay (PLA) (D, box plot summarizing results) showing an increased frequency of NLRP3-ASC complexes in PE placentae compared with controls. (E) Graph showing an inverse correlation between platelet counts and cleaved IL-1β in human placentae obtained from women without pregnancy complications (controls; C; black) or with PE (gray). Arrowheads indicate inactive (proform, white arrowheads) and the active (cleaved-form, black arrow heads) form of Casp-1 or IL-1β, respectively (A). Only the active form was quantified (B). Size bar represent 20 µm (C). Data shown represent mean ± SEM. Data obtained from 5 independent experiments (A) or from 15 (B) or 5 (D) different placentae per group. *P < .05 (relative to control, C); #P < .05 (relative to EV); **P < .0005 (relative to control placentae, C). (B,D) Nonparametric Mann-Whitney U test; (E) Spearman correlation.